In the first year of the project, work has been initiated which explores both the experimental and theoretical problems of interpreting the circular dichroism sepctrum of proteins. The experimental problems center around a) the preparation of proteins in chemically and structurally pure state; b) obtaining a high information content C.D. spectrum, preferably ranging into the vacuum ultraviolet region of the spectrum; c) identification of chromophoric anomalies originating from aromatic residues. In this situation iodination of tyrosyl residues in the protein provides an insight into potentially "abnormal" electronic contributions from such tyrosine residues. The theoretical investigation has taken the form of extending our nearest neighbor approach relating the C.D. spectrum to phi, psi space to the use of xi, eta space that involves a transform of phi, psi coordinates to symmetry related cylindrical space. So far the analysis of lysozyme and nuclease suggests that anomalies of determining beta-sheet structures from C.D. spectra may arise from subtle super-twisting which can produce strongly modified spectra. In the coming year, xi, eta analysis of several proteins will be completed so that comparisons between experimental spectra and bond symmetry may be made.